The length, narrow valves, and distinct nature of the central nodule help to distinguish this species from other linear taxa such as N. recta, in which the striae are not visible and N. intermedia, which is smaller in size and lacks a distinct central nodule.

LM scalebar = 10 µm
Nitzschia linearis LM2 Nitzschia linearis LM3 Nitzschia linearis LM1 Nitzschia linearis LM5 Nitzschia linearis LM4
Length Range
60-150 µm
Width Range
4-6 µm
Striae in 10 µm

Nitzschia recta

Hantzsch ex Rabenh. 1862

Nitzschia recta LM7 Nitzschia recta LM5 Nitzschia recta LM6 Nitzschia recta LM3 Nitzschia recta LM8
Length Range
48-85 µm
Width Range
4.7-7 µm
Striae in 10 µm

Also compare to

Nitzschia intermedia

Hantzsch ex Cleve and Grunow 1880